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doc-exports/docs/dli/sqlreference/dli_08_0180.html
Su, Xiaomeng 04d4597cf3 dli_sqlreference_0511_version 
Reviewed-by: Pruthi, Vineet <vineet.pruthi@t-systems.com>
Co-authored-by: Su, Xiaomeng <suxiaomeng1@huawei.com>
Co-committed-by: Su, Xiaomeng <suxiaomeng1@huawei.com>
2023-11-02 14:34:08 +00:00

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AS for Table

Function

This statement is used to specify an alias for a table or the subquery result.

Syntax

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SELECT attr_expr_list FROM table_reference [AS] alias;

Keyword

  • table_reference: Can be a table, view, or subquery.
  • As: Is used to connect to table_reference and alias. Whether this keyword is added or not does not affect the command execution result.

Precautions

  • The to-be-queried table must exist. Otherwise, an error is reported.
  • The alias must be specified before execution of the statement. Otherwise, an error is reported. You are advised to specify a unique alias.

Example

  • To specify alias n for table simple_table and visit the name field in table simple_table by using n.name, run the following statement:
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    SELECT n.score FROM simple_table n WHERE n.name = "leilei";
  • To specify alias m for the subquery result and return all the query results using SELECT * FROM m, run the following statement:
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    SELECT * FROM (SELECT * FROM simple_table WHERE score > 90) AS m;
Parent topic: Alias